Grand Street Campus and Eli Rodriguez topped John Adams, 8-4, in the opener of the PSAL Class A best-of-three semifinal series on Friday. Photo: William Thomas

It can be the loneliest place in sports, the pitcher’s mound. Just not now. Just not at 9:48 p.m. on the first of June, at the end of the 8,020th game in the history of the New York Mets.

Now, Johan Santana is peering in at a St. Louis Cardinals hitter named David Freese — and all Freese has on his résumé is a World Series MVP — and the count is 3-and-2, and there are 27,069 people inside Citi Field who are on their feet and millions of invisible fans scattered elsewhere holding their breath. The score is 8-0, but that became irrelevant a long time ago.

Johan Santana is about to throw a change-up, his best pitch, the pitch that made him a star, that made him a millionaire, that has delivered him to this moment, 9:48 p.m., 26 outs in the books, one more for the first no-hitter in Mets history. He should feel like the loneliest man in the world.

Yet he isn’t. There are the 27,069 people, of course, and 50 years worth of Mets fans who have endured Jimmy Qualls and Leron Lee, Kit Pellow and Paul Hoover, lifetimes landscaped by the belief that while they may have lived long enough to see two Mets world championships, they would never — ever — see a no-hitter.

Inside the home dugout, there is a manager who can barely keep himself from weeping every few minutes. Two innings earlier, he’d approached Santana in the dugout, asked how he was feeling, was told all was well, and that’s when Terry Collins almost lost it. Instead, he had a simple message for his pitcher.

“You’re my hero,” he said.

Upstairs, in the SNY television booth, Ron Darling also fights a dry throat and moist eyes. He is part of the roster of names Mets fans have always summoned, a team with a pitching-rich history that has never gotten the 27th out. Seaver … Koosman … Ryan … Gooden … Darling … Fernandez … Saberhagen … Leiter … Martinez …

“The biggest honor of my life is being a part of that legacy, hearing my names listed with the roster of names of the men who have pitched for this team,” Darling will say later. “And I’ve waited along with everyone else. And always hoped it would be a name of royalty who got this done. A Tom Seaver. A Dwight Gooden …”

He will pause and catch himself, for neither the first nor the last time.

“A Johan Santana.”

Not far from where Darling works sits Jordan Sprechman, the official scorer for this game. The closest Gooden ever came to a no-hitter with the Mets, in September of his rookie year, Keith Moreland reached on a single that could have been called either way. The next day, at the U.S. Open, John McEnroe was at a press conference when he spotted the scorer.

“Hey!” McEnroe barked from the podium. “How could you call that a hit?”

Sprechman has already seen how an umpire can get embroiled in such a splendid night, Adrian Johnson helping to recalibrate Santana’s gem when he didn’t see the chalk fly up from what probably should have been a Carlos Beltran double in the sixth. Even that early in the game, Sprechman said to himself, “Better him than me.”

Now, he is hoping for either three clean outs or one clean base hit.

“The ninth inning of a no-hitter,” Sprechman will say, “is when this job changes from being attentive to being on edge.”

So yes, they are all there, sharing the mound with Johan Santana, who has thrown 133 pitches with a surgically salvaged left arm, who has all but told his manager that he will not give him the ball unless he’s shot with a tranquilizer dart. Who has already seen one teammate all but donate a shoulder to the cause. And keeps thinking about one thing:

“Mets fans deserve this.”

And so he throws a change-up to a World Series hero, and Freese freezes and swings feebly, and 27,069 people make a sound like 72,069 people, and Mets charge from the dugout, and Johan Santana has done it, he has done it he has DONE IT …

And Terry Collins cries. And so does Ron Darling. And even if you are a Mets fan wounded by the past few years, come clean: you did too. And in his home in New Jersey, watching with his son, Dylan, one of those fans, sitting on the edge of his couch, bursts into a forever smile on a forever night.